ui: P2 polish batch (trees, motion, chrome)

lib/core/motion/querya_cross_fade_stack.dart

@@ -5,6 +5,9 @@ import 'querya_motion_context.dart';
 
 /// Like [IndexedStack] but cross-fades the active child; off-screen children
 /// stay mounted (preserves SQL editor state, etc.).
+///
+/// Enter/exit curves and index clamping match [QueryaSwitchingBody] (without
+/// the optional slide).
 class QueryaCrossFadeStack extends StatelessWidget {
   const QueryaCrossFadeStack({
     super.key,
@@ -17,26 +20,29 @@ class QueryaCrossFadeStack extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    assert(children.isNotEmpty, 'QueryaCrossFadeStack requires children');
+    final safeIndex = index.clamp(0, children.length - 1);
     final duration = context.motionDuration(QueryaMotion.standard);
-    final curve = context.motionCurve(QueryaMotion.enter);
+    final inCurve = context.motionCurve(QueryaMotion.enter);
+    final outCurve = context.motionCurve(QueryaMotion.exit);
 
     return Stack(
       fit: StackFit.expand,
       children: [
         for (var i = 0; i < children.length; i++)
           Positioned.fill(
             child: IgnorePointer(
-              ignoring: index != i,
+              ignoring: i != safeIndex,
               child: ExcludeFocus(
-                excluding: index != i,
+                excluding: i != safeIndex,
                 child: ExcludeSemantics(
-                  excluding: index != i,
+                  excluding: i != safeIndex,
                   child: AnimatedOpacity(
-                    opacity: index == i ? 1 : 0,
+                    opacity: i == safeIndex ? 1 : 0,
                     duration: duration,
-                    curve: curve,
+                    curve: i == safeIndex ? inCurve : outCurve,
                     child: TickerMode(
-                      enabled: index == i,
+                      enabled: i == safeIndex,
                       child: RepaintBoundary(child: children[i]),
                     ),
                   ),

lib/core/motion/querya_hover_surface.dart

@@ -4,6 +4,10 @@ import 'querya_motion.dart';
 import 'querya_motion_context.dart';
 
 /// Unified hover background / border using motion tokens (Responsive chrome).
+///
+/// **Scope:** selection / picker cards (e.g. connection type tiles). Dense
+/// trees and explorer rows keep lighter `InkWell` / `MouseRegion` hover —
+/// do not broaden adoption without an explicit follow-up.
 class QueryaHoverSurface extends StatefulWidget {
   const QueryaHoverSurface({
     super.key,

lib/core/motion/querya_stagger.dart

@@ -31,6 +31,7 @@ class _QueryaStaggerState extends State<QueryaStagger>
     with SingleTickerProviderStateMixin {
   late final AnimationController _controller;
   bool _played = false;
+  Duration _effectiveStep = kQueryaStaggerStep;
 
   @override
   void initState() {
@@ -47,12 +48,13 @@ class _QueryaStaggerState extends State<QueryaStagger>
     if (n == 0) return;
 
     final base = context.motionDuration(QueryaMotion.fast);
+    _effectiveStep = context.motionDuration(widget.step);
     if (base == QueryaMotion.instant) {
       _controller.value = 1;
       return;
     }
 
-    final total = base + widget.step * n;
+    final total = base + _effectiveStep * n;
     _controller.duration = total;
     _controller.forward();
   }
@@ -96,7 +98,7 @@ class _QueryaStaggerState extends State<QueryaStagger>
     final totalMs = _controller.duration!.inMilliseconds;
     if (totalMs <= 0) return 1;
 
-    final stepMs = widget.step.inMilliseconds;
+    final stepMs = _effectiveStep.inMilliseconds;
     final start = (stepMs * index) / totalMs;
     final end = (start + 0.35).clamp(0.0, 1.0);
     final t = _controller.value;

lib/core/sdui/sdui_tree_builder.dart

@@ -4,6 +4,7 @@ import 'package:querya_desktop/core/motion/querya_motion_context.dart';
 import 'package:querya_desktop/core/sdui/sdui_tree_schema.dart';
 import 'package:querya_desktop/core/ui/querya_icon_sizes.dart';
 import 'package:querya_desktop/core/ui/querya_icons.dart';
+import 'package:querya_desktop/core/ui/querya_tree_tokens.dart';
 import 'package:querya_desktop/shared/widgets/widgets.dart';
 
 /// Renders a sidebar-style tree from an SDUI schema with lazy expansion.
@@ -174,7 +175,9 @@ class SduiTreeBuilderState extends material.State<SduiTreeBuilder> {
         final row = rows[index];
         if (row.isError) {
           return material.Padding(
-            padding: material.EdgeInsets.only(left: 36.0 + row.depth * 16.0),
+            padding: material.EdgeInsets.only(
+              left: 36.0 + row.depth * QueryaTreeTokens.indent,
+            ),
             child: material.Align(
               alignment: material.Alignment.centerLeft,
               child: Text(row.error!).muted().xSmall(),
@@ -196,7 +199,6 @@ class SduiTreeBuilderState extends material.State<SduiTreeBuilder> {
   material.Widget _buildNodeRow(SduiTreeNode node, {required int depth}) {
     final theme = Theme.of(context);
     final muted = theme.colorScheme.mutedForeground;
-    final primary = theme.colorScheme.primary;
     final canExpand = node.expandable || node.hasChildren;
     final isExpanded = _expanded.contains(node.id);
     final isLoading = _loading.contains(node.id);
@@ -205,8 +207,11 @@ class SduiTreeBuilderState extends material.State<SduiTreeBuilder> {
     // Same hierarchy as native trees (#476 / #497) — no separate sduiNode size.
     final iconSize =
         canExpand ? QueryaIconSizes.treeGroup : QueryaIconSizes.treeLeaf;
-    final iconColor = isBrowsable ? primary.withValues(alpha: 0.5) : muted;
-    final rowLeft = 8.0 + depth * 16.0 + (canExpand ? 0 : 4.0);
+    final iconColor = isBrowsable
+        ? QueryaTreeTokens.leafIconColor(theme.colorScheme.primary)
+        : muted;
+    final rowLeft =
+        8.0 + depth * QueryaTreeTokens.indent + (canExpand ? 0 : 4.0);
 
     return material.InkWell(
       onTap: () {

lib/core/ui/querya_icons.dart

@@ -14,7 +14,7 @@ abstract final class QueryaIcons {
       material.Icons.account_tree_rounded;
   static const material.IconData schema = material.Icons.diamond_rounded;
   static const material.IconData extension = material.Icons.extension_rounded;
-  static const material.IconData publicSchema = material.Icons.public_rounded;
+  static const material.IconData foreignData = material.Icons.hub_rounded;
 
   static const material.IconData tableGroup =
       material.Icons.table_chart_rounded;
@@ -23,11 +23,18 @@ abstract final class QueryaIcons {
   static const material.IconData viewLeaf = material.Icons.view_week_rounded;
   static const material.IconData materializedViewGroup =
       material.Icons.dynamic_feed_rounded;
+  static const material.IconData materializedViewLeaf =
+      material.Icons.layers_rounded;
   static const material.IconData functionGroup =
       material.Icons.functions_rounded;
   static const material.IconData functionLeaf = material.Icons.code_rounded;
-  static const material.IconData sequence =
+  static const material.IconData sequenceGroup =
       material.Icons.format_list_numbered_rounded;
+  static const material.IconData sequenceLeaf =
+      material.Icons.looks_one_rounded;
+
+  /// Alias kept for call sites that still say "sequence" as the group icon.
+  static const material.IconData sequence = sequenceGroup;
   static const material.IconData indexes = material.Icons.table_rows_rounded;
   static const material.IconData triggers = material.Icons.bolt_rounded;
   static const material.IconData types = material.Icons.category_rounded;

lib/core/ui/querya_tooltip.dart

@@ -0,0 +1,2 @@
+/// Shared [Tooltip.waitDuration] for dense chrome (trees, grids, …).
+const Duration kQueryaTooltipWait = Duration(milliseconds: 450);

lib/core/ui/querya_tree_tokens.dart

@@ -0,0 +1,14 @@
+import 'package:flutter/material.dart';
+
+/// Shared connection-tree metrics and colors (PG / MySQL / SQLite / SDUI).
+abstract final class QueryaTreeTokens {
+  /// Indent for schema rows and sibling object folders under a database.
+  static const double indent = 16;
+
+  /// Leaf-row icon tint (tables, views, sequences, …).
+  ///
+  /// Takes [primary] (not [ColorScheme]) so both Material and shadcn schemes
+  /// can pass `.primary` without a type clash.
+  static Color leafIconColor(Color primary) =>
+      primary.withValues(alpha: 0.5);
+}

lib/features/connections/connections_panel.dart

@@ -68,6 +68,8 @@ import 'package:querya_desktop/core/storage/local_db.dart';
 import 'package:querya_desktop/core/theme/querya_typography.dart';
 import 'package:querya_desktop/core/ui/querya_icon_sizes.dart';
 import 'package:querya_desktop/core/ui/querya_icons.dart';
+import 'package:querya_desktop/core/ui/querya_tooltip.dart';
+import 'package:querya_desktop/core/ui/querya_tree_tokens.dart';
 import 'package:querya_desktop/core/motion/querya_animated_expand.dart';
 import 'package:querya_desktop/core/motion/querya_motion.dart';
 import 'package:querya_desktop/core/motion/querya_motion_context.dart';

lib/features/connections/connections_panel_mysql.dart

@@ -668,7 +668,9 @@ class _MysqlObjectGroupState extends State<_MysqlObjectGroup> {
                   label: item,
                   icon: widget.itemIcon,
                   iconSize: QueryaIconSizes.treeLeaf,
-                  iconColor: theme.colorScheme.mutedForeground,
+                  iconColor: QueryaTreeTokens.leafIconColor(
+                    theme.colorScheme.primary,
+                  ),
                   textStyle: material.TextStyle(
                     fontSize: 11,
                     color: theme.colorScheme.foreground,

lib/features/connections/connections_panel_pg_tree.dart

@@ -48,7 +48,7 @@ class _PgTreeRowLabel extends material.StatelessWidget {
     if (label.length < _tooltipMinLength) return text;
     return material.Tooltip(
       message: label,
-      waitDuration: const Duration(milliseconds: 450),
+      waitDuration: kQueryaTooltipWait,
       child: text,
     );
   }
@@ -381,7 +381,7 @@ class _PgDatabaseNodeState extends State<_PgDatabaseNode> {
                   connection: widget.connection,
                   databaseName: widget.databaseName,
                   label: 'Foreign data',
-                  icon: QueryaIcons.publicSchema,
+                  icon: QueryaIcons.foreignData,
                   kind: PostgresObjectKind.databaseForeignData,
                   onPostgresObjectSelected: widget.onPostgresObjectSelected,
                   onPostgresOpenSqlWorkspace: widget.onPostgresOpenSqlWorkspace,
@@ -682,7 +682,7 @@ class _PgSchemaNodeState extends State<_PgSchemaNode> {
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
     return material.Padding(
-      padding: const material.EdgeInsets.only(left: 12),
+      padding: const material.EdgeInsets.only(left: QueryaTreeTokens.indent),
       child: material.Column(
         crossAxisAlignment: material.CrossAxisAlignment.start,
         mainAxisSize: material.MainAxisSize.min,
@@ -794,7 +794,7 @@ class _PgSchemaNodeState extends State<_PgSchemaNode> {
                     onRefresh: _loadObjects,
                     label: 'Materialized views',
                     icon: QueryaIcons.materializedViewGroup,
-                    itemIcon: QueryaIcons.materializedViewGroup,
+                    itemIcon: QueryaIcons.materializedViewLeaf,
                     items: _matviews,
                     onItemTap: widget.onPostgresObjectSelected != null
                         ? (name) => widget.onPostgresObjectSelected!(
@@ -837,8 +837,8 @@ class _PgSchemaNodeState extends State<_PgSchemaNode> {
                         widget.onPostgresOpenSqlWorkspace,
                     onRefresh: _loadObjects,
                     label: 'Sequences',
-                    icon: QueryaIcons.sequence,
-                    itemIcon: QueryaIcons.sequence,
+                    icon: QueryaIcons.sequenceGroup,
+                    itemIcon: QueryaIcons.sequenceLeaf,
                     items: _sequences,
                     onItemTap: widget.onPostgresObjectSelected != null
                         ? (name) => widget.onPostgresObjectSelected!(
@@ -1045,7 +1045,9 @@ class _PgObjectGroupState extends State<_PgObjectGroup> {
                   label: item,
                   icon: widget.itemIcon,
                   iconSize: QueryaIconSizes.treeLeaf,
-                  iconColor: theme.colorScheme.primary.withValues(alpha: 0.5),
+                  iconColor: QueryaTreeTokens.leafIconColor(
+                    theme.colorScheme.primary,
+                  ),
                   textStyle: material.TextStyle(
                     fontSize: 11,
                     color: theme.colorScheme.foreground,

lib/features/connections/connections_panel_sqlite.dart

@@ -398,7 +398,9 @@ class _SqliteObjectGroupState extends State<_SqliteObjectGroup> {
                   label: item,
                   icon: widget.itemIcon,
                   iconSize: QueryaIconSizes.treeLeaf,
-                  iconColor: theme.colorScheme.mutedForeground,
+                  iconColor: QueryaTreeTokens.leafIconColor(
+                    theme.colorScheme.primary,
+                  ),
                   textStyle: material.TextStyle(
                     fontSize: 11,
                     color: theme.colorScheme.foreground,

lib/features/main_screen/result_grid_view.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart' as material;
 import 'package:flutter/services.dart' show Clipboard, ClipboardData;
 import 'package:querya_desktop/core/layout/ui_scale.dart';
+import 'package:querya_desktop/core/ui/querya_tooltip.dart';
 import 'package:shadcn_flutter/shadcn_flutter.dart';
 
 /// Layout metrics for [VirtualResultGrid].
@@ -485,7 +486,7 @@ class _GridCell extends material.StatelessWidget {
 
     return material.Tooltip(
       message: text,
-      waitDuration: const Duration(milliseconds: 400),
+      waitDuration: kQueryaTooltipWait,
       child: interactiveCell,
     );
   }

lib/features/main_screen/workspace_empty_hero.dart

@@ -182,22 +182,31 @@ class _WorkspaceEmptyHeroState extends State<WorkspaceEmptyHero> {
                   QueryaFadeSlide(
                     alignment: material.Alignment.topCenter,
                     offset: const material.Offset(0, 0.03),
-                    child: showRecent
-                        ? _RecentConnectionsSection(
-                            key: const material.ValueKey('empty_recent_section'),
-                            connections: _recent,
-                            onOpenConnection: widget.onOpenConnection,
-                            compact: compact,
+                    child: !_loaded
+                        ? const material.SizedBox(
+                            key: material.ValueKey('empty_section_loading'),
+                            height: 120,
                           )
-                        : _QuickStartSection(
-                            key: const material.ValueKey('empty_quick_start'),
-                            compact: compact,
-                            surface: wb.surface,
-                            borderColor:
-                                wb.borderSubtle.withValues(alpha: 0.55),
-                            foreground: cs.foreground,
-                            primary: cs.primary,
-                          ),
+                        : showRecent
+                            ? _RecentConnectionsSection(
+                                key: const material.ValueKey(
+                                  'empty_recent_section',
+                                ),
+                                connections: _recent,
+                                onOpenConnection: widget.onOpenConnection,
+                                compact: compact,
+                              )
+                            : _QuickStartSection(
+                                key: const material.ValueKey(
+                                  'empty_quick_start',
+                                ),
+                                compact: compact,
+                                surface: wb.surface,
+                                borderColor:
+                                    wb.borderSubtle.withValues(alpha: 0.55),
+                                foreground: cs.foreground,
+                                primary: cs.primary,
+                              ),
                   ),
                 ],
               ),

lib/features/updater/update_dialog.dart

@@ -3,6 +3,8 @@ import 'dart:io';
 
 import 'package:flutter/material.dart' as material;
 import 'package:querya_desktop/core/layout/window_layout.dart';
+import 'package:querya_desktop/core/motion/querya_motion.dart';
+import 'package:querya_desktop/core/motion/querya_motion_context.dart';
 import 'package:querya_desktop/core/theme/querya_theme_scope.dart';
 import 'package:querya_desktop/core/updater/app_updater_service.dart';
 import 'package:querya_desktop/core/updater/update_manifest.dart';
@@ -273,7 +275,24 @@ class _UpdateDialogContentState extends material.State<_UpdateDialogContent> {
                   horizontal: 24,
                   vertical: 8,
                 ),
-                child: _body(context),
+                child: material.AnimatedSwitcher(
+                  duration: context.motionDuration(QueryaMotion.standard),
+                  switchInCurve: context.motionCurve(QueryaMotion.enter),
+                  switchOutCurve: context.motionCurve(QueryaMotion.exit),
+                  layoutBuilder: (currentChild, previousChildren) {
+                    return material.Stack(
+                      alignment: material.Alignment.topCenter,
+                      children: [
+                        ...previousChildren,
+                        if (currentChild != null) currentChild,
+                      ],
+                    );
+                  },
+                  child: material.KeyedSubtree(
+                    key: material.ValueKey(_phase),
+                    child: _body(context),
+                  ),
+                ),
               ),
             ),
             material.Container(